Telegraphone.



H.' R. STUART.

TELBGRAPHONE. APPLICATION FILED MAR. 21

Patliied Oct. 12, 1909.

- UNITED i sTATEs PATENT. orrrcn. HAnvE n. STUART, orWHELINGwEsTvIRGINI, AssIGNoB, To AMEiucAN TELEG- mPHoNn COMPANY, ACORPORATION or THE DISTRICT or coLUrrBIA.'

TELEGRPHONE.

936,490. Specification of Letters Patent.

t Application led March 21', 1908. Serial No. 422,399.

To all whom 'it may concern:

I Se it known that I, HARVE R.- STUART, a c1t1zen of the United States,residing at Wheeling, in the county of Ohio and State of West Virginia.,have invented certain new and useful Improvements in Telegraphones, ofwhich the following is a full, clear, .and

' exact description.

' This invention relates to telegraphones ofl that class in which therecording steel body 1s in the form of a disk. In this kind of machlne,it is well known that if the disk runs at a uniform speed, the recordwill be weaker as 1t approaches the center of the disk, on account ofthe peripheral speed with respect to the magnet growing less as thediameter decreases. Speed governors are not always desirable, andsometimes cannot be relied upon for accu-rate graduatioirof speed as themagnet shifts its position.' lonsequently, two magnets, one moving fromthe periphery toward the center and theother from the center toward theperiphery, and both conupon one face of the disk, while the other" Ahasbeen arranged to act upon the opposite.

' face,'both magnets being fed radially the entire distance from theperiphery to the hub. Under some conditions, however., ,it is A notconvenient or feasibleto operate a magnet on each side of the disk.

My invention therefore consists, broadly,

in locating the two magnets both on the same side of the disk, leavingthe other side free. In this arrangement, each magnet can act upon onlyone-half of the recording surface, so that the capacity is reduced inthat proportion, butfor some purposes this is not material, and when thereducedA capacity is not material, the advantage of a clear space on theopposite side of the disk isgained.

My invention is illustrated 1n the accompanying drawing, in which F1 ure1 is a side elevatlon of a conventiona form'of my invention inwhich thetwo magnets are located onV opposite sides of the center of the disk.Fig. 2 is a similar view of a form of the invention in whichtwo magnetslare mounted on a` single frame which is fed by a single screw. Fig. 3is a similar view inwhich the two magnets are located on opposite sidesof the center of the disk, but travel the entire distance across therecording surface, the spiral path traced by one alternating with thattraced by the other; and Fig. 4 illustrates the path of the two magnetswhen arranged as in Fig. 4.

Referring to the drawings, 1 indicates the recording body in the form ofa disk, it being mounted upon a central rota ting shaft 2. Arrangedparallel to one face of the disk Patented oct.- 12,o 1909.

is a feed screw 2 to be rotated in any suitable j the hub, while thethread at the other endof the screw is opposite the inner half of therecording surface which lies between the suitable carriers which areprovided with a. nut or threaded portion 8 and engage the respectivethreaded portions 4 and 5` of the feed screw. ,The magnets are so placedupon their respective threads that when one'of .them is at the extremeouter position, the

other isat the extreme inner position of the respectlve recordingsurfaces. When i the machlne is 1n mot1on, the magnets uniformly 'shifttheir relative positions, both of them traveling in the same direction,as indicated by the arrows.V The'record produced and reproduced by themagnet 6 will always be stronger than that produced and reproducedby themagnet 7 because it acts upon a portion of the disk which is moving at ahigher speed than that portion ofthe disk which is acted upon by themagnet 7. But,

4ao point a, and the hub. Therecording magnets indicated by 6 and 7 aremounted upon atI all times, since the magnets are connected in the samecircuit, the record produced and reproduced by the magnet 6 will beaugmented by that produced and reproduced by the magnet 7. Since themagnets change their radial positions uniformly, one grow-v ing weakerwhile the other'- grows stronger,

the sum of the record produced and repro- I' In the arrangement shown inFig. 2, the

capacity of the` disk remains the same as in the arrangement of Fig. 1,and the strength of the record produced and repro- A` duced is also'thesame, but the two magnets the recording surface.'

are here mounted upon a single frame 9 which requires a single nut 8 anda single feed screw.

Inl Fig. 3, the two magnets aie locatedv upon opposite sides of thecenter of the disk, but each travels the full radial width of In orderto prevent one of these magnets from tracing the saine spiral path onthe disk which is traced by the other, and thereby causing interferenceof the two magnetic records, the'pitch of the threads on-the feedingscrew are made coarser, or the pitch and width of the record path madeless, and one inagnet'is so placed upon the screw that it will trace aspiral line, the turns of which will alternate with those of the spiralline traced by the other magnet, as clearly illustrated in Fig. 4,wherein the full line indicates the path of one magnet, and the dottedline the path of the other. llith this arrangement, the capacity ofthedisk is the same as in the other4 structures and the production andreproduction of the recordre-mainsthe same.

What I claim, is:

l. In a telegraphone, the combination of a recording body in the'form ofa disk, two telegraphone magnets located upon the same side of the disk,and means for moving one of the magnets from a point on the disk runningat high speed to a point at lower speed and for moving the other magnetsimultaneously and uniformly therewith from a point on the disk runningat low speed to one runningat a higher speed, substantially asdescribed.

2. In a telegraphone, the combination of a recording body in the form ofa disk, two

telegraphone magnets located on the saine side ofthe disk, said magnetsbeing located upon opposite sides of the center of the disk and feedingmechanism for moving .said mafrnets simultaneously in a substantiallyradial direction, one magnet from a position on the vdisk of hiUh speedtoward a position of low speed, anda the other from a posit-ion on thedisk of low speed to 'one of higher y speed.

In witness whereof, I subscribe my signature, in the presence of twowitnesses.

- HARVE R. STUART.

lvitnesses FRANK S. OUii,

WALDo M. CHAPIN.

